Submarine detector



April 9, 1946. A. wlKsTROM I SUBMARINE DETECTOR 2 sheets-sheet@ Filed March 24, 1943 HIS AT T ORNEY April 9, 1946. A wlKsTROM 2,397,995

SUBMARINE DETECTOR Filed March 24, 1943 2 Sheets-Sheet 2 '0 FIG'. 5

FIG. 5

IN V EN TOR. RNE WI KSTROM HIS ATTORNEY Patented Apr. 9, 1946 SUBMARINE DETECTOR Arne Wikstrom, Glen Echo Heights, Md.

Application March 24, 1943, Serial No. 480,321

Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) This invention relates in general to detecting devices, and particularly is a device intended to locate a submerged submarine when direct visual observation is not possible and then to give a surface indication oi such location. It will be obvious, however, from the following description that the detector will function equally well to detect mines, sunken hulls of ships and other objects made of or containing magnetic material; and, therefore, while the invention, in this description, may be termed a submarine detector, this expression is not to be taken as restrictive.

One object of the invention is to produce a submarine detector including a powerful magnet for causing the detector to be attracted to a submerged submarine, and means providing an indication at the surface of the water when a detector has located a submarine.

Another object is to produce a submarine detector adapted to sink in the water, but including a member adapted to oat to the surface when a submarine is encountered by the detector.

A further object is to provide in a submarine detector adapted to sink in the water means for causing the device to float after a time lapse whether or not a submarine is encountered by it.

A still further object of the invention is to provide in a submarine detector yadapted to sink in the water means for causing the device to oat after a certain predetermined depth has been reached by it.

It is also an object of the invention to provide in a submarine detector comprising two members adapted to separate upon the locating of a, submarine, a iiexible cord or wire for connecting the two members after separation.

Additional objects will be apparent from a reading of the following specication and claims.

In the drawings:

Figure 1 is an elevation of the detector of the invention, showing the same in normal condition, ready for operation, the upper portion thereof being broken somewhat for convenience of illustration.

Figure 2, also in elevation, and including only a portion of the upper end of the detector, illustrates the relations of the parts immediately after contact with a submerged submarine or other magnetic body.

Fig. 3 is a vertical section midway through the magnet used in the invention, and showing also certain elements associated therewith.

Figure 4 is a top view of the structure of Fig- Figure 5 is a bottom View of the structure of Figure 3.

Figure 6 is a sectional view of a portion of the buoyant member of the invention, illustrating the means for reiioating a detector.

In general, the invention comprises a magnet portion or member, and-a float member normally locked to the magnet member by means of a spring-pressed latch, and means for opening the latch when the magnet secures itself to a metal body.

Referring to the drawings, ill is the magnet which causes the device to be attracted to certain metallic bodies. The magnet shown is of permanent type, and horseshoe in form although substantially cylindrical in section. The horseshoe magnet, with its small air gap, has been found to be most desirable from the standpoint of strength in relation to weight. Preferably, since the greatest possible strength is sought, a permanent magnet of Alnico, an alloy consisting of aluminum, iron, nickel and cobalt, has been used.

Extending vertically through the center of the magnet IIJ is -a sleeve II (see Figure 3), formed of non-magnetic material, such as brass. This sleeve, or at least so much thereof as is in alignment with the air gap, is cut oli somewhat short of the bottom of the magnet, as at I2 An opening I3, restricted at I4, may be seen extending vertically through the sleeve.

Arranged for axial movement in the sleeve II is a rod i5, the diameter of which is selected to provide an easy sliding fit in the sleeve restriction Ill. Secured to the lower end of rod I5 is a member I 6, which may be termed a trigger, and this is adapted for sliding movement vertically in the air gap of the magnet, and is, of course, of non-magnetic material. Surrounding rod I5, between trigger I6 and the restriction I4 of sleeve II, is a spring I1, which functions to maintain rod I5 with trigger I5 in the extended condition shown in Figures 1 and 3.

'Ihe diameter of rod I5 decreases above magnet I0, as at I8, and this change in diameter provides a cam action as will be further described.

Secured to sleeve II, above the magnet, are two spring members I9 and 20. Member 29 is bent inwardly at 2|, and then outwardly, and is provided at its upper end with a semicircular latching element 22, with an upper dished surface 22'. Member I9 is formed similarly, and has a latchlng element 23, with a dished surface 23. The clearance between members I9 and 20, where they are bent inwardly, is approximately the same as tion thereof an enlargement 28 of such size and nature as to receive for free sliding movement therein the upper portion of magnet l0, and to provide a seat 29 to limit the movement of the magnet into the sleeve.

In the center of sleeve2'l, and supported from cylinder 24, is a post-like member 3U, with a circular enlargement or ange 3l on the lower end thereof somewhat larger than the opening through latch members 22 and 23 when the same are in closed relatiornbut smaller than' theopening therethrough *when the latch members are open. AFlange 3l is tapered at v32. Post 39 is bored out in its center, at 33, to receive the upper end'of rod 5,05 the magnet assembly.

The manner inV which the parts nt together will be readily apparent. With the parts of the magnet and latching structure in the relations shown in Figure 3, this structure is merely slid into opening 28 inV sleeve 2l. The top of rod I5 enters opening 33 in member 3&3 and aids in guiding the parts together.r The tapered flange 3i cooperates with the dished surfaces 22' and 23 of latch members Z2 and 23 to force'these members apart so that they pass easily over the flange. Springs I9 and 20 then close the latch members above the ilange. With the lower at surfaces of the latch members resting on the upper flat surface of the :flange 3l, the elements are securely fastened together.

It will be understood that, in addition to the sleeve il and trigger i6, the'various other elements `of the structure-with the exception of the magnet itselfare formed of non-magnetic material.

In use, these devices are intended to be strewn relatively thickly over an area in which an object sought to be discovered is believed to be located. Since the devices sink slowly, and sincethe mag netic elements are very strong, it is likely, if the object sought really is within the suspected area,

that one or more of the detectors will be attracted thereby. Assuming that one is so attracted, it will fasten itself to the body, and in so doing will force the trigger Iii upwardly against the action of spring il. Movement ofthe trigger of course produces a like movement of rod l5, and enlargement i8 thereof is forced between the spring members i3 and 20, thereby opening the latches 22 and 23, whereupon the freed buoyant body 24 iioats to the surface.

Openings 34, 35 and 36 are provided in sleeve 2l, in order that no difference in pressure above and below the magnet Ill may tend to prevent easy disengagement or the buoyant cylinder 24.

Secured to the upper portion of the detector is a spool 3l, which is adapted toV rotate freely in the brackets 3l and 31", and this spool contains a fine wire 38, one end of which is secured to magnet element l0, as by screw 3S. As willbe apparent, this arrangement provides a connection between the buoyant bodyV 24 and any subi Y terial.

' tered by the detector.

marine or other magnetic body toV which element lil may have secured itself.

The exact indicating means to be used in connection with the device is not a part of this invention, but certain possibilities will be pointed out. For use in daylightand in restricted areas,V

the floating cylinder itself, especially if brightly painted, may provide enough of a signal. For night operation, an upwardly directed light may be provided in body 24, with a battery, and a switch actuated by withdrawal of rod I5, or by some other convenient means.

As so lfar described,the detector of this inventionA will sink in the water, and the buoyant member 2li will iioat to the surface only if and when a submarine or other magnetic body is encoun- Since the devices are to be used in large quantities, however, they will represent considerable expense, notwithstanding the unit cost is small. Under some combat conditions, therefore, and in salvaging operations, it will be desirable to collect and re-use the detectors. The means for accomplishing this end are illustrated in Figure 6. Y

The vstructure of the device is fundamentally just fas has been described; The weights ofthe elements are proportioned somewhat differently, however, so that, with cylinder 2li empty, the detector will iloat rather than sink.. Liquid ballast, which may be a solution of sodium carbonate, is introduced through the opening 25 in a quantity suilicient to give the detector a negative buoyancy, and cap 2t is screwed on. Y, y

-In the lower part of cylinder 2t is a flask or chamber lle, with a small opening lli at the bottom thereof, the opening normally being sealed by a small pellet e2 of wax or other suitable ma- The top of flask de communicates with the exterior of cylinder 2li through a pipe or tube 3, in the outer, enlarged, end oi which is arranged a pressure-sensitive piston 44, which acts against a spring e5. A seat fl Vis provided for the piston, to limit Vits outward movement.- A rod 46, in the tube e3, serves as a guide for the piston. The lpiston is substantially watertight, noV matter what its position. The ilask l is `filledfwith sulphuric acid. v i .Y

Extending from the lower part of cylinder v.24 to the top portion thereof is a pipe or tubei5ll,l

which also commiuiicates with the exterior'ofcylinder Zt. The outer end of the pipe contains a Vvalvei which acts-in a direction opposite to piston @li-#against a spring 52. A seat 53 is provided for thevalve. v

The action of this' arrangement is simple. As the detector sinks in the water, piston 44 is gradually pressed inwardly, increasing the pressure on the acid in flask 40. When the pressure rises suilciently, pellet 42 will be forced off opening-4I, and the acid will be introduced slowly into the sodium carbonate solution, thereby to decompose the solution, and free carbon dioxide gas. action continues, and becomes increasingly fast as pressure on piston 44 increases. At some point, when the pressure inside .chamber 24 `is greater than that outside, the liquid ballast will that has located a submarine, and one that hasY not, valves, ballast, etc., are so calculated/that there will be a definite, prolonged, time lapse ,be-y tween the return to the surface of the formerand the latter. Further, of course, when smoke Thev or light signals are combined with the detector, such signals are to be actuated only in the event that the buoyant member has become separated from the magnetic element.

By varying the size of opening 4I, and the nature and means for securing thereto pellet 42, the blowing of the ballast can readily be made to depend primarily on either depth or duration of submersion.

The foregoing description is in specific terms; and for the true scope of the invention, reference should be had to the appended claims.

This invention may be manufactured and/or used by or for the Government of the United States of America Without the payment of any royalty thereon or therefor.

Iclaim: n Y n Y 1. A device ofthe character described including a magnet element for automatic engagement with a body containing magnetic material, a buoyant member, releasable means normally securing the buoyant member to the magnet element and means releasing said securing means upon engagement of the magnet element with said body.

2. A device of the character described including a magnet element adapted to secure itself to a body containing magnetic material, a latching member on said element, a buoyant element and a latching member thereon adapted normally to cooperate with the rst mentioned latching element to secure the buoyant element to the magnet element, and means operative upon the securing of the magnet element to a body containing magnetic material for unlatching the normally cooperating latching elements.

3. A device of the character described including an element for automatic engagement with a body containing magnetic material, a buoyant member, releasable means normally securing the buoyant member to said element, and a trigger actuated by engagement of said element with a body for releasing said securing means.

4. A device of the nature described including a magnet having a surface for securing the magnet to a body containing magnetic material, a trigger normally projecting beyond said surface and adapted to be actuated when the magnet is secured to a body, and a buoyant body normally fixed to said magnet but adapted to be released upon the actuation of said trigger.

5. A device of the character described including a magnet having a surface for securing the magnet to a body containing magnetic material, a buoyant body, spring closed latching means normally securing the buoyant body to the magnet, a trigger normally spring pressed beyond the said magnet surface but adapted to be moved substantially flush with said surface when the magnet is secured to a body containing magnetic material, and means cooperating with said trigger for opening the latching means when the trigger is moved.

6. In a device of the character described, a

buoyant member having a lower cylindrical portion open at the bottom, a magnet element in said cylindrical portion adapted to secure itself to an object containing magnetic material, means for normally securing together said member and said element, means for releasing said securing means, and means for equalizing pressure above and about said element.

'7. A structure according to claim 1, further characterized by means for ballasting the device. and means actuated by pressure external of said device for blowing the ballast.

8. A structure according to claim l, further characterized by means for ballasting the device with a liquid ballast, and means actuated by pressure external of said device for producing pressure above said liquid ballast for driving the same out cf said device.

9. A structure according to claim l, further characterized by means for ballasting the device with a liquid ballast, an outlet for said ballast, a valve for said outlet, said valve being normally closed but adapted to be opened by an increase in pressure on said ballast, and means actuated by pressure external of said device for increasing the pressure on said ballast.

10. A structure according to claim 1, further characterized by a flexible extensible connection between the buoyant member and the magnet element.

ARNE WIKSTROM. 

